1. Field of the Invention
The present invention is directed to a food oven which utilizes both convection and conduction of hot air.
2. Prior Art
Ovens which heat by convection of hot air as well as by conduction of hot air are widely utilized, including in commercial food preparation.
Conduction occurs by heat radiating from a heat source above, below, or both above and below the food within the oven.
Convection is accomplished by circulating hot air past a heat source through use of a fan which circulates the air through the oven.
In order to improve the output of these ovens, a conveyer mechanism is sometimes incorporated. The uncooked food is placed at one end of the conveyer. The conveyer drive mechanism is timed so that after passing through the oven, the food is fully cooked. The conveyer, which may include a continuous belt, must be constructed so that it may be periodically removed for cleaning or maintenance.
A goal for commercial food preparation ovens is to reduce the cooking time to a minimum and increase the throughput rate to maximize the quantity of food cooked.
In order to maximize production, high heat within the oven is desirable. If the convection fan is downstream of the heat source, the fan is subject to extremely high heat which strains and wears the fan. Additionally, the fan motor and oven controls should be shielded from extreme heat. A further concern in commercial ovens is to prevent burn injuries to employees. While insulation may be utilized around the walls of the cooking chamber, the temperature may still become excessive.
Prior art patents illustrate various features of existing ovens. Smith (U.S. Pat. No. 3,884,213) discloses a microwave oven having heating elements upstream from a fan which delivers hot air to columnar heat transfer jets.
Riech (U.S. Pat. No. 3,933,145) discloses a barbecue device having a fan which forces air beneath a basin for holding coals and then upward toward the food grill.
Howe (U.S. Pat. No. 4,420,679) discloses an oven having a pivotal inner baffle door and a fan to circulate air downstream of a heating source.
Burtea (U.S. Pat. No. 4,576,090) provides an oven wherein heated air is drawn past a burner tube by a fan blower downstream of the burner and then directed to perforated plates.
Smith et al. (U.S. Pat. No. 4,750,276) provides an axial fan downstream of heating elements providing convection flow of hot air onto food.
Hanke et al. (U.S. Pat. No. 4,462,383) provides an impeller fan downstream of a heat source which forces heated air into a plenum for focusing heat on the food. An adjusting mechanism is provided at one end of a conveyer frame for adjusting tension of a wire link belt.
It is a principal object and purpose of the present invention to provide an oven wherein the temperature delivered to the food is at an optimum while the temperature of the oven controls and other components is reduced.
It is a further object and purpose of the present invention to provide an oven with a conveyer mechanism whereby the conveyer may be disassembled and reassembled for periodic cleaning without use of tools.
It is a further object and purpose of the present invention to provide a cooling shell around the exterior of the cooking chamber and about the controls.